Siemens ISOLATED MULTI-DROP SG-6048-01 - Manual (Page 16)

Appendices
Siemens Energy & Automation, Inc. 13
Appendix A: Block Diagram
The illustration below is a block diagram showing how the Isolated Multi-Drop converter operates.
The diagram identifies the internal components that make up the converter.
Figure A.1. Block Diagram
25-pin D
Connector
RXD
TXD
RTS
DCD
Signal
Ground
RS-232
Transceiver
3
2
4
8
7
Galvanically Isolated
RS-485 Logic
Tx Enable
+
-
SHIELD
RS-485
Port 1
Tx Enable
+
-
SHIELD
RS-485
Port 2
Tx Enable
+
-
SHIELD
RS-485
Port 3
Tx Enable
+
-
RS-485
Port 4
Earth Ground Baud
Switch
Tx
Enable
Logic
RTS/DCD
AUTO/MAN RTS
DCD
MAN
AUTO
RS-232
Connector
Earth Ground
+
-
External 15V DC output
Isolated
Supply
5V
Power Supply
5V
15V
120 VAC/
Source
125 VDC
DC
DC
SHIELD
Opto-isolators
for each data
channel
RS-485
Transceiver (4)